A continuing problem in many industrial processes is the disposal of industrially generated wastes. Pollution control laws prohibit the disposal of waste materials in ways which contaminate the environment. Consequently, the discharge of many gaseous products and particulate materials to the atmosphere, the discharge of liquid and solid waste into bodies of water, and even the disposal of liquids and solids on land are restricted. A desirable and convenient way to dispose of wastes is to destroy them by complete combustion of the wastes. Disposal by combustion is especially useful and potentially economical for wastes which are at least in part combustible. Substantially complete combustion requires a heating value for liquid waste of at least about 90,000 BTU per gallon, and air in the amount of at least about 7.5 pounds per 10,000 BTU.
Many residues are not completely converted to innocuous substances when burned in the open, and many devices and processes have been suggested for disposing of waste by combustion processes. However, the burning of many wastes presents problems. EPA regulations require 99.9 percent combustion efficiency together with a minimum burning temperature and retention time at burning temperature for combusting hazardous wastes. In order for these requirements to be met, it is necessary for the waste to burn with consistent heat values and burning characteristics. However, many wastes comprise a mixture of various substances, and may comprise mixtures of liquids and solids, the components of which have heating values from about zero to very high levels. The waste may comprise a mixture of components having different specific gravities such that these components separate upon standing. Further, different liquid fractions may have different viscosities and/or concentrations of solids. Highly viscous liquids, and liquids containing solids, can plug burner nozzles, stopping the flow of combustible liquids and causing the flame to go out. Further, many wastes contain a sufficient amount of water so that they are incapable of supporting combustion. While such liquids can be mixed with liquids having a high enough BTU value so that the mixture is combustible, the aqueous phase tends to separate from the mixture. This solution, i.e., that of adding a sufficient amount of high BTU liquid to make a combustible mixture, is inefficient in its use of the heating value of the waste.